Mark Klein, Whistleblower Who Exposed NSA Internet Surveillance, Dies at 79

The former AT&T technician revealed the NSA's mass data collection program years before Edward Snowden's disclosures.

Mark Klein, a retired AT&T technician, exposed the NSA's use of secret facilities to monitor vast amounts of U.S. internet traffic in 2006.
Klein's revelations detailed how optical splitters at AT&T hubs copied internet data into secure NSA-controlled rooms, such as Room 641A in San Francisco.
His disclosures supported lawsuits against AT&T and the NSA, though these efforts were ultimately dismissed after Congress granted immunity to telecom companies in 2008.
Klein's actions preceded and inspired further whistleblowing, including Edward Snowden's 2013 revelations of mass surveillance programs.
Klein passed away on March 8, 2025, at age 79 from pancreatic cancer, leaving a legacy of exposing government overreach and advocating for privacy rights.